In order for aircraft seating to be certified for use in an aircraft, the seat must pass a series of performance tests to ensure that it will withstand the various dynamic forces that it may be subjected to, particularly in an emergency situation. In order to be certified as airworthy, aircraft seating designs must pass a series of dynamic tests that simulate aircraft deformation and impulse loading during emergency conditions.
Also, weight is a very significant factor in designing any structure for an aircraft. Weight relates directly to fuel consumption. For this reason every effort is made to design structures to be used in aircraft to be as light as possible consistent with other requirements. One of these other requirements is passenger safety. A seat could be built heavily and sturdily enough not be bend or break during an aircraft accident merely by fabricating it of heavy steel or of thick, solid aluminum. However, the weight penalty is so great that the use of such structures is economically impractical.
Thus, aircraft seating must be strong enough to not only support the weight of the seat occupant, but also to withstand the various load forces that are generated as a result of aircraft maneuvers performed by the pilot during flight, upon landing or, more importantly, in the event of an emergency. These various load forces are known as “g-forces” and result from the forces of acceleration that push or pull on the seat and its occupant when the pilot changes the motion of the aircraft.
G-forces can be positive or negative and can result from either an acceleration or deceleration of the aircraft. In addition to acceleration loads encountered in flight, g-loads are also experienced during periods of rapid acceleration or deceleration such as occurs during the takeoff and landing phase of a flight. These g-forces exert a rearward force with respect to the aircraft during periods of acceleration, thereby forcing one back into the seat on takeoff, and a forward force during the period of deceleration on landing, thereby pulling one forward in the seat. Further, lateral g-forces can be experienced when the aircraft turns, forcing the occupant sideways across the seat if the aircraft seat is set sideways (such as a divan), as can be in a business jet.
During a normal take-off, landing, and maneuvers, a passenger absorbs this g-loading by shifting in the seat; forward, backwards, and into the seatbelt. In the event of an emergency or crash landing, however, the seat frame itself must be capable of absorbing high g-loads without being deformed or, even worse, snapped out of the floor of the aircraft. This is particularly true of a sideways facing seat.
Conventional seats that supply the structure necessary to withstand the emergency g-forces from the aircraft are also very heavy. Presently ways to absorb the g-forces required by Federal Aviation Administration (“FAA”) regulations and produce a lighter seat, are difficult, with the seat still being heavy. Thus, there is a need for a lighter weight aircraft seats that can absorb the same load.